Coaxial WO3/TiO2 nanotubes/nanorods with high visible light activity for the photodegradation of 2,3-dichlorophenol

It is well known that the structural disorder of photocatalyst nanopowder usually leads to the enhanced scattering of free electrons, and thus reduces the electron mobility: in contrast, an ordered and interconnected nanostructure favors to improve electron transport, then achieving the higher photocatalytic efficiency. Therefore, in this study, a highly ordered and coaxial WO3/TiO2 nanostructure, consisting of nanotubes and nanorods, was prepared by a sot-gel template technique. The obtained photocatalysts were characterized by FE-SEM, XRD, UV-vis DRS and PL measurement. These photocatalysts exhibited a strong photoresponse in the visible region and a low PL emission. Their photoactivity was evaluated by means of the degradation of 2,3-dichlorophenol (2,3-DCP) under visible light irradiation. Experimental results show that while there was no obvious degradation of 2,3-DCP with the TiO2 nanotubes as photocatalysts, similar to 53% of degradation degree in 300 min was obtained with the WO3/TiO2 nanocomposites. This significant activity should be attributed to the role of WO3 loaded in TiO2 nanotubes. The WO3 loading not only facilitates the effective separation of photogenerated carriers occurring on the TiO2 surface, but also enhances the surface hydroxyl groups and surface acidity, thus improving the overall photocatalytic performance. (C) 2011 Elsevier B.V. All rights reserved.